• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.10A
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• pp.1695-1705
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• 2001

기존의 셀룰러 IP (CIP : Cellular IP) 프로토콜을 개선하기 위해, 본 논문에서는 각 노드에 통합된 페이징 및 루트 정보관리 캐시(PRC)를 구성하고, 그리고 각 노드 및 이동호스트가 핸드오프-상태모드를 갖는 개선된 셀룰러 IP(ECIP : Enahnced CIP) 프로토콜을 제안하였다. ECIP 프로토콜에 대하여 패킷 유실, 핸드오프 지연 및 네트워크 내 트래픽 부하 특성 등을 고찰한 결과, ECIP는 액세스 네트워크 내 노드와 이동호스트의 수, 노드 내 다운링크의 수, 그리고 네트워크 내 페이징 캐시의 분포비율이 증가할수록 CIP와 비교하여 크게 개선되었다.

• Proceedings of the ESK Conference
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• 1996.04a
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• pp.236-249
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• 1996

본 연구의 목적은 높은 직업적 작업부하(Work stress)에 노출되어 있는 경찰들이 사 용하는 개인보호장비를 대상으로 사용자 중심의 설계기준에 기초한 인간공학적인 분석과 개선을 통하여 경찰의 임무수행도의 향상은 물론 직업에 따른 신체적인 안전과 건강의 향상을 도모하는데 있다. 주요 연구대상 장비는 방석복, 헬멧, 방패였으며, 개선의 주요 사항으로는 장비별 무게의 경감, 열압박의 감소와 통풍성의 향상, 사용성과 안전성을 향 상시킨 재질과 구조적인 개선을 가져왔으며 개선안에 대한 시제품을 제작하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.323-328
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• 2004

Domestic Design-Build, which has applied for client's convenience, has many problems Because It is being applied in the building law, which devides between architects and contractors. Among problem the relation between architects and contractors is a typical problem. It makes a quality decline and a design skill decline. In result, it causes insufficience of competitive power in overseas projects from now on. So we present the plans to improve mutual relations between architects and contractors. And we induce development of design skill and good quality of building by presenting a coordinative committee model between them in Design-Build projects.

• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.819-832
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• 2004

This study describes an efficient and facile method for configuration optimum design of structures. One of the ways to achieve numerical shape representation and the selection of design variables is using the design element concept. Using this technique, the number of design variables could be drastically reduced. Isoparametric mapping was utilized to automatically generate the finite element mesh during the optimization process, and this made it possible to easily calculate the derivatives of the coordinates of generated finite element nodes w.r.t. the design variables. For the structural analysis, finite element analysis was adopted in the optimization procedure, and two different techniques(the deterministic method, a modified method of feasible direction; and the stochastic method, a genetic algorithms) were applied to obtain the minimum volumes and section areas for an efficient configuration optimization procedure. Futhermore, spline interpolation was introduced to present a realistic optimum configuration that meet the manufacturing requirements. According to the results of several numerical examples(steel structures), the two techniques suggested in this study simplified the process of configuration optimum design of structures, and yielded improved objective function values with a robust convergence rate. This study's applicability and capability have therefore been demonstrated.

• Journal of the Korea Society for Simulation
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• v.15 no.3
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• pp.93-101
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• 2006

Recently, work-related musculoskeletal disorders (WMSDs) become a hot issue in the industrial fields. To prevent the potential risk of workers, various approaches have been adopted. One of the approaches is to improve the design of product, that of jig (or fixture) and that of workstation in the early stage of the development. 3D simulation technology is known as the powerful method for detecting such problems before constructing the workstation, because it is possible to evaluate the posture of worker using 3D models in a cyber space. It enables to find the unexpected problems and save the time and cost for redesign and rework. This paper introduces a 3D simulation case study of workers in an excavator factory. 3D models of products, jigs were developed with CATIA. The assembly processes were animated in IGRIP and DPM. Finally the various postures of worker were simulated using Human. As a result, some postures were analysed as the risky jobs and the result of simulation was used to improve the system.

• Korean Journal of Optics and Photonics
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• v.16 no.4
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• pp.334-339
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• 2005

We studied the spatial filtering characteristics of a multi-phase hologram optical low-pass filter(HOLF). Using the Monte-Carlo based hologram generation program, we designed holograms whose diffraction patterns are circular shaped 21 beams and calculated the diffraction efficiencies and MTFs. 4-phase HOLF have the same diffraction efficiency as that of 2-phase HOLF. The MTF graphs of the two are also nearly alike. But 8-phase HOLF shows higher efficiency than those previously discussed and has larger MTF values in the low frequency region. 16-phase HOLF has just a little better characteristics than 8-phase. Considering the errors which can arise in the process of making holograms, 8-phase HOLF fits the goal of improving the resolution of spatial filter. We also fabricated 8-phase HOLF and .measured MTF The experimental results agree well with the theoretical expectations.

• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.351-359
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• 2019

Recognizing that the fundamental cause of construction safety accidents was a lack of safety management activities in the planning and design phases, the government made the Design for Safety (DFS) system mandatory in May 2016. However, awareness among ordering parties and designers regarding this system is significantly low, and the system has not been properly established due to reasons such as the need for additional work and a lack of professional manpower. In this study, the awareness of ordering parties and designers of the DFS system was analyzed through a survey, various problems in DFS work execution were identified and measures for improvement were presented. Measures to improve the efficiency in DFS work execution involve the discovery of risk factors and establishment of countermeasures, and here the establishment of a DFS work support system that enables the sharing of information between institutions is the most urgent priority. In addition, it is also urgently necessary to establish a dedicated organization in charge of DFS work, cultivate professional manpower, develop the relevant education programs and establish a proper cost calculation standard for DFS work execution by design offices.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.304-313
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• 2020

By using an off-axial field with an inverse Cassegrain system where the aperture stop is at the secondary mirror, the two-mirror system can be used for a wide-field objective. However, aberration corrections in conventional two-mirror systems are limited because the design parameters are too small. In this study, we present a new improved design of the off-axial-field two-mirror system. The new design has an independently displaced aperture stop and a secondary mirror. The new design parameters yield more improvement in correction for 5th-order coma and astigmatism, and better aberration balancing for the whole off-axial field. The spot sizes of the new design system are reduced to half of those for a conventional reference design, and the improvement effects are shown for the whole field evenly.

• Nuclear industry
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• v.20 no.7 s.209
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• pp.32-38
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• 2000

• Korean Architects
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• no.4 s.432
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• pp.18-19
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• 2005